ruby 嵌套函数
嵌套直到循环 (Nested until loop)
Alike for, while, and do...while, until loop can also be nested for meeting the specific purpose. In this type of nesting, two until loops work in the combination such that at first, the outer loop is triggered which results in the execution of the inner loop. The outer Until loop is not invoked as long as the inner loop does not comes out to be true. It is a kind of Entry control loop which simply means that first the outer Boolean expression is processed; if it is false then the pointer will move to the inner loop to check inner condition. The whole execution will take place in the same manner.
与for， while和do ... while一样 ， 直到循环也可以嵌套以满足特定目的。 在这种嵌套中，两个直到循环在组合中起作用，这样一来，首先触发外循环，从而执行内循环。 只要内部循环不成立，就不会调用外部的直到循环。 这是一种Entry控制循环，仅表示首先处理外部布尔表达式；然后进行处理。 如果为假，则指针将移至内部循环以检查内部条件。 整个执行将以相同的方式进行。
Syntax:
句法：
until conditional [do]
until conditional [do]
# code to be executed
end
# code to be executed
end
Example 1:
范例1：
=begin
Ruby program to find the sum of numbers lying
between two limits using nested until loop
=end
puts "Enter the Upper limit"
ul=gets.chomp.to_i
puts "Enter the Lower limit"
ll=gets.chomp.to_i
until ul==ll
num=ul
temp=ul
sum = 0
until num==0
#implementation of until loop
rem=num%10
num=num/10
sum=sum+rem
end
puts "The sum of #{temp} is #{sum}"
ul=ul-1
end
Output
输出量
Enter the Upper limit
1000
Enter the Lower limit
980
The sum of 1000 is 1
The sum of 999 is 27
The sum of 998 is 26
The sum of 997 is 25
The sum of 996 is 24
The sum of 995 is 23
The sum of 994 is 22
The sum of 993 is 21
The sum of 992 is 20
The sum of 991 is 19
The sum of 990 is 18
The sum of 989 is 26
The sum of 988 is 25
The sum of 987 is 24
The sum of 986 is 23
The sum of 985 is 22
The sum of 984 is 21
The sum of 983 is 20
The sum of 982 is 19
The sum of 981 is 18
Example 2:
范例2：
Pattern printing: Print the following pattern
图案打印：打印以下图案
0
01
012
0123
01234
Code:
码：
=begin
Ruby program to print the given pattern.
=end
num=0
until (num==6)
j=0
until(j==num)
print j
j+=1
end
puts ""
num+=1
end
翻译自: https://www.includehelp.com/ruby/nested-until-loop-with-examples.aspx
ruby 嵌套函数
